I think that it would be more transparent if they made this perfectly clear to gmail users when they are signing up rather than relying on them inherently knowing this (or reading it buried somewhere in the TOS). I doubt that the majority of Gmail users (or just Google Account holders) realize this.
I'll say this, though. If a majority of your customers do not realize the full implications of what their terms are with you, then you are either:
1) Actively trying to prevent your customers from learning about the terms.
2) Relying on the general naivety of your customers.
3) Incompetent, in that you're not doing your job of letting your customers know what they are signing up for.
If more people were fully aware of the fact that their Gmail account could be randomly closed at any time, without notice, but still used the service because they accepted the risk, then it would be a different story.
I'll say this, though. If a majority of your customers do not realize the full implications of what their terms are with you, then you are either:
1) Actively trying to prevent your customers from learning about the terms.
2) Relying on the general naivety of your customers.
3) Incompetent, in that you're not doing your job of letting your customers know what they are signing up for.
If more people were fully aware of the fact that their Gmail account could be randomly closed at any time, without notice, but still used the service because they accepted the risk, then it would be a different story.