I'm guessing there would be a lot of repeat IP addresses being used if people used VPN a lot. Really tough to monitor traffic or restrict access to accounts.
Try and find a different provider, both my current providers recommend to use VPN while using the service. To answer your question, some providers don't want to deal with the hassle of multiple IP addresses for accounts or account sharing. I can't use any service that doesn't allow for multiple IP addresses and VPN usage.
Should ALWAYS use a VPN, this protects you and the provider, I have no idea what they are thinking
Forbidding a VPN would be a no-go for me. My ISP definitely feels like it slows down my connection if I don't use a VPN for IPTV.
The two providers I use work fine with the two VPNs I use. Redundancy is key. If one combo won't work, the other usually will. I never watch anything except Youtube in the clear.
Iptv works better without VPN whatever they say. Still plenty of services not needing VPN.
A couple of other reasons that VPN usage isn't desired would be non-optimal routing, MTU sizing issues, and client issues associated with CPU overhead. I haven't had any issues with Comcast tampering with IPTV traffic that is not VPN'd up to this point so haven't used one. I wouldn't want to be on a service that didn't allow VPN though since they'd probably be more likely to want to lock you to an IP address and you never know when a VPN will be required.
I need to find a provider that allows vpn.
Definitely don't use a provider that doesn't allow you to use a VPN. The solution is to find a new provider that doesn't IP lock or restrict VPNs.