i think you are right because as far as reading books is concerned with un prejudiced mind then the most probable answer which we derive is that mahmood ghaznavi was not a mujhahid waging jihad of any sort.
if we strictly confine our thinking to this aspect then we find many clues which clearly show that this man was more interested in money then in jihad.
the following strong points which i could gather are these.

1.rajput has offered him a strong resistance,in retaliation mahmood decided to send regular expeditions against them.hence mahmood was on their gates every year.it was his revenge against them becaz they had offered him combined resistance.not jihad.becaz jihad is always pure with no other intentions other than fight in the way of Allah.

2.indian kingdoms of nagarkot,kanauj,thaneswar,gawalior,ujjain etc.were all conquered but if he had islamic motives he would not have handed them over to hindus or buddhists but he did this.he made alliances with hindus.
here too no islamic motive.

3.but after this he directed his attention to temples becaz they were the centre of wealth,and were also economic and ideological centres.
he wanted to loot them,destroy them politically.thats why he attacked thaneswar,mathura,kanauj,somnath etc.

these temples were the centres of brahmans who were quite influential caste of that period.destroying them was equal to destryoing the might of indian states.

the most haunting thing for hindus even to this date is mahmoods invasion of Somnath.it was a centre of Brahman religion.
as this centre needed money so they befooled the local villagers that this idol of somnath will transmigrate their soul into a better and richer man when they will come in another body.in this way they were able to collect income of ten thousand villages.its wealth was to much.and it was filled with jewels.

there was a chain of gold weighing 200 maunds.all this was too much to think of.sultan who had spent too much on these expeditions needed this wealth to finance the war.

so i think it is most probable that mahmood ghaznazi was just an ordinary conquerer who came looted and went away.he left no imprints just destroyed temples and that too not in love of islam but because of his craze for money.

and one thing which is realted to the concept of jihad is that in islam there is no concept of destroying the temples or churches or the religious centres of any religion.there are countless examples in islamic history when muslims didn't even touched the temples of idol worshipers.

so i think it is not justified to call his expeditions a jihad.But i will try to find other aspect of the story too.