How online casinos make money

Online casinos in general are profitable operations with a typical net margin of 50% of wagering volume (i.e they earn $50 for every $100 wagered).

Smaller casinos including startups that do not have high profit margins are the ones that typically impose unfavorable restrictions as they have less room to deal with the small percentage of players that are bonus abusers.  In the cases I've mentioned a smaller casino like SunVegas will use large bonus payouts with the imposition of much higher cashout restrictions compared to a casino like Intercasino.  This is done to maximize profits in order to grow their businesses.

Online casinos are in business to make money. Ideally this is done through generating enough wagering volume in order for the house edge to take effect. There is a fine balance between offering attractive bonuses fairly and discouraging players from returning by imposing ridiculous cashout terms.