Many customers have asked me why proposals always seem excessively long. This is often the case early in the process, when the buyer is simply looking to engage a new system integrator. Even if the customer does not ask for fixed price or fixed scope and keep the tender at less than 10 pages, many system integrators and vendors respond with proposals that are more than 100 pages (10 times longer).
Naturally the ideal scenario for you as a buyer, would be that all the received proposals were of a high quality, but that is rarely the case. Even in these challenging times, most bidders deliver copy-and-paste jobs and have simply added lengthy standard responses to each requirement. Sales people - like many others - are lazy, and rather than producing fresh, concise, case-specific material, they often add a bunch of ultimately irrelevant files; appendixes with product datasheets, annual reports, training courses, case studies, project methodologies, corporate background and history are not rare.
As a customer you want to make sure that you treat everybody fairly and provide a reasonable cause for disqualifying a bidder. However, reading through thousands of pages is very time-consuming.
In my view, you should indicate early on that you will simply disqualify any proposal that is longer than your tender. If the vendor does not have any more respect for your time, and are unable to summarize their qualifications, you should look for somebody more capable. Call me old-fashioned, but I would also disqualify a bidder with too many typos. If the bidder is unable to start off with high quality, what makes you expect that the quality will come later?