The nature of these attacks, ironically (or not) are often very similar to the innuendos and lies that are often spread about the beliefs of Shi'a Muslims - whose rights the progressives, from time to time, pretend to champion as "proof" of their being above and beyond sectarianism.
The reality is that the way progressives attack and twist beliefs of "traditionalists" is so similar to those we might call 'takfiris" that they show themselves to be a flip side of that movement. And so, progressive muslims will throw around statements that traditionalists believe in slavery, that they do not pray towards the Qibla, that they think wife rape is condoned in the Shari'a etc. Much of the basis for these statements are taken from this or that fatwa, web sites, or discussion boards. While there may be elements of "truth" it is not the whole truth, and the intention is to malign and distort, not to seriously engage in discussions about Shari'a and religious beliefs.
This is the same kind of sectarianism that is often engaged against Shi'a Muslims - whose statements and beliefs are distorted by taking this or that phrase off some site, and spreading 'em around the web, or through fitna pamphlets. This is also exactly the same methodology used by anti-Muslim right wing fanatics - whose blogs are filled with all kinds of one liner nonsense. As such, the Progressive Islam/Muslim types are much closer in their methodologies of attacks to the takfiries on the one hand, and anti-Muslim right wing fanatics on the other.
The Mind Body Soul blog has an entry on these attacks that is worth a read:
Those who follow Islam as it has been understood for centuries have to deal with attacks on multiple fronts, there is certainly no respite in being known as a ‘traditionalist’.
... the progressive/reformists/modernists whose theology is so plainly confused that they don’t even think it is worth discussing. It is difficult to believe they revere anything, either that, or they view expressive reverence as a form of weakness.
To speak of them, first we must identify them. This is difficult to do as they plainly avoid discussion of their own religious beliefs and their ideological heroes are often non-Muslim.
One of their defining characteristics is their enjoyment to dip into taboo’s. In fact the more taboo the subject, the better it is for them to discuss (better search-engine keywords). The most interesting aspect of their reactionary approach is that, like most short lived movements, they rely intimately on criticisms of the other to define themselves.
What is quite curious is that there is not one among them that has actually come from a background of traditional learning.
Lacking a fundamental understanding of what they spend their hours criticising, their mistakes in their understanding of tradition are visible from afar. This latest post from Ali Eteraz, lists a number of things he applies to the traditional understanding of Islam. His immediate mistake of making the lead financing state of the Wahabi philosophy, Saudi Arabia, into following the “Hanbali legal code”. As if Shaykh Abd al Qadir Jilani (rad) would have approved of this mockery of a legal code in Wahabistan.