My company builds out enterprise and b2b apps. For most of our clients, infrastructure just isn't a big enough expense to really think about or optimize for. If you're selling your web app at a $1,000-$10,000 a license per year it doesn't really matter what you spend on servers. But it still matters how much time/money you spend managing your servers. So here it makes a lot of sense to go cloud because it's a lot faster to go from having no infrastructure to running a web server and database with automatic backups.