As to the reason for Jeroboam's rebellion, I will base my answer on five main points.
1) Assault on Israel's cultural and religious identity by Solomon's foreign alliances.
1 Kings 11:1,4 (NKJV)
But King Solomon loved many foreign women, as
well as the daughter of Pharaoh: women of the Moabites, Ammonites,
Edomites, Sidonians, and Hittites -- For it was so, when Solomon was
old, that his wives turned his heart after other gods; and his heart
was not loyal to the LORD his God, as was the heart of his father
These passages tell us about the growing influence of foreign cultures, both linguistic, religious and ethnic inside Israel at that time. These cultural dilution was sponsored by the palace and would have disrupted social harmony.
2) Heavy tax burdens that served the interests of foreigners:
a) Solomon would have had to increase the tax burden to feed and house his 700 foreign wives (princesses) and 300 concubines along with their children and retinue of attendants.
b) Peasant Israelites were toiling to finance the offering of huge amounts of grain, wine, oil and livestock to the multiple foreign gods that Solomon had introduced due to the nudging of his foreign women.
c) Naturally, there would have been competition between the wives and their children for a place in the Davidic dynasty. This kind of political intrigue would have been socially damaging since the competing forces were non-native. This would have increased the general level of dissent considerably.
3) The endless building projects embarked upon by Solomon:
a) The temple which took about seven years to complete
b) His own palace which took thirteen years to build 1-Ki 7:1
c) House of the forest of Lebanon 1-Ki 7:2
d) Hall of Pillars 1-Ki 7:6
e) Hall of the throne and the Hall of judgement 1-Ki 7:7
f) Palace for Pharaoh's daughter 1-Ki 7:8
g) Other houses, pools, gardens and orchards e.t.c
which had to be arduously tended in an arid environment
Ecclesiastes 2:4-7 (NKJV) I made my works great, I built myself
houses, and planted myself vineyards. I made myself gardens and
orchards, and I planted all [kinds] of fruit trees in them. I made
myself water pools from which to water the growing trees of the grove.
I acquired male and female servants, and had servants born in my
house. Yes, I had greater possessions of herds and flocks than all who
were in Jerusalem before me.
These building projects required a lot of quarrying, artisanship and logging. And they continued almost endlessly throughout Solomon's reign due to his desire to find fulfillment and immortality in these endeavors.
4) Ancient arrogance of the Ephraimites along with the Ephraim vs Judah rivalry (Jos 7:14-17, Judg 8:1 & 12:1):
1 Kings 11:28 (NKJV)
The man Jeroboam was a mighty man of valor; and
Solomon, seeing that the young man was industrious, made him the
officer over all the labor force of the house of Joseph.
So we can see that Solomon had pooled a labour force from each of the tribes. But the tribes of Joseph had always had a superiority complex from the days of Joshua, Gideon and Jephtah. This prolonged subservience to Judah resurrected it.
Whenever there is cultural dilution within a society people tend to react by taking refuge in their specific identities e.g race, ethnicity and so on. I believe that at that time, many were taking refuge in their tribes and the largest and most illustrious tribes in Israel were the tribes of Ephraim and Manasseh.
5) The conspiracy and support from the religious leaders in Israel:
Jewish history tells us that religious leaders have always been formidable power brokers in Israel. From prophets like Moses to Joshua. From Joshua to Samuel. From Samuel to Nathan and Gad. This community was responsible for the emergence and consolidation of David on the throne. Losing the support of this community was enough to cause a rebellion.
1 Kings:11.29-31 (NKJV)
Now it happened at that time, when Jeroboam went out of Jerusalem,
that the prophet Ahijah the Shilonite met him on the way; and he had
clothed himself with a new garment, and the two [were] alone in the
field Now it happened at that time, when Jeroboam went out
of Jerusalem, that the prophet Ahijah the Shilonite met him on the
way; and he had clothed himself with a new garment, and the two were
alone in the field
Then Ahijah took hold of the new garment that was on him, and tore it
into twelve pieces. And he said to Jeroboam, "Take for yourself ten
pieces, for thus says the LORD, the God of Israel: 'Behold, I will
tear the kingdom out of the hand of Solomon and will give ten tribes
To understand this point, we have to use the witness of Rehoboam to provide insight into just how oppressive Solomon had become.
1 Kings 12:4,11 (NKJV)
"Your father made our yoke heavy; now therefore,
lighten the burdensome service of your father, and his heavy yoke
which he put on us, and we will serve you." 'And now, whereas
father put a heavy yoke on you, I will add to your yoke; my father
chastised you with whips, but I will chastise you with scourges!' "
The tribes of Israel under the leadership of Jeroboam had complained about the burdensome yokes of Solomon. Rehoboam the son of an Ammonitess doesn't deny their claims. He even admits that his father chastised them with whips.
So under such suffering, the early support of respected religious leaders like prophet Ahijah would have been enough to embolden Jeroboam to rebel.
All in all, the writer of this story tells us that "God raised enemies against Solomon". So the unseen hand of God is the final answer to this question.