Please advice on a small question

This request we often hear from customers who doesn't want to sign technical support contract.
And who get angry, when we decline to perform consulting of this kind.
Therefore we'll try to clarify politics regarding this question and reasons that stay behind this.
The possibility to work for our company is based on:

According to signed contracts we plan human resources in our company, or vice versa, we take new contracts according to human resources we have currently.
In case if we loose our contracts, especially long-term, due to poor quality or bad response timing, we may close our company.
Therefore performing tasks for the contracts with a best possible quality and with the best timing - is our main aim.
Serving questions from customers, with whom we doesn't have contracts, introduces risk of failure to comply already sighed contracts with other customers, in case if human resources will be distributed not the way it was planned to fulfill contracts.

Consulting customers, with whom there is no contract, also has several drawbacks:

At the moment we don't have dedicated specialists, who could serve technical questions from customers, with whom we have no contract.
To permanently employ such specialists we need finances which should be included into price which is paid by contract customers.
This would significantly decrease competitiveness and will be unfair for contract customers.
Therefore questions from customers without contract and answered after performing works for other contract customers, during free time of technical specialists.

Exceptions:
1. Сrisp question, which has short answer and doesn't require diagnostics and clarifications.
2. In case if question in already answered in this Wiki, for example:

Other question we recommend to gather in Technical request document.
Then, when there is enough of questions, negotiate and sign 1-month contract for technical support with work on these questions.
Or sign contract for long-term support (Service-level agreement).
See also Differences between long-term SLA support and 1-month technical support according to Technical request

We hope for understanding in this question.

Русский перевод