there were a few reasons.
- getting kicked off, because i received 1 single DMCA
- getting threatened to forward my personal details to official authorities, since i didn't react within 2 hours (and they personally haven't liked some of the content)
- having hardware-failures (hdd raid crashed, due to corrupt HDD) and the provider won't change the hdd
- downtime more than 2 hours per Month on regular basis
- slowliness of IO and LAN (so typically oversold)
- need for bigger/lower hardware (e.g. more CPU, RAM, transfer) due to new projects (or closing down projects)
- having a provider forcing me to use some strange config-panel installed
- host loosing the ability to pay my invoices via Service X (e.g. PayPal, credit card)
- support not reacting within a reasonable time (based on the money i spend per month: within one hour and a few days)
- comparable server for less money (and i'm not talking about 1$. It was more than 30$ per month)
- not providing newer versions of the software (expecially for hypervisors)